From d2f119fe319528da8c76a1107459d6f478cbf28c Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Mon, 3 Jul 2006 12:02:35 -0400 Subject: [PATCH] [PATCH] ieee1394: nodemgr: switch to kthread api, replace reset semaphore Convert nodemgr's host thread from kernel_thread to kthread and its sleep/restart mechanism from a counting semaphore to a schedule()/ wake_up_process() scheme. Signed-off-by: Stefan Richter Signed-off-by: Ben Collins --- drivers/ieee1394/nodemgr.c | 120 +++++++++++++------------------------ 1 file changed, 41 insertions(+), 79 deletions(-) diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c index 04b62eca64..2e6dc5990c 100644 --- a/drivers/ieee1394/nodemgr.c +++ b/drivers/ieee1394/nodemgr.c @@ -12,8 +12,8 @@ #include #include #include -#include #include +#include #include #include @@ -163,11 +163,7 @@ static DECLARE_MUTEX(nodemgr_serialize); struct host_info { struct hpsb_host *host; struct list_head list; - struct completion exited; - struct semaphore reset_sem; - int pid; - char daemon_name[15]; - int kill_me; + struct task_struct *thread; }; static int nodemgr_bus_match(struct device * dev, struct device_driver * drv); @@ -1477,9 +1473,8 @@ static void nodemgr_node_probe(struct host_info *hi, int generation) /* If we had a bus reset while we were scanning the bus, it is * possible that we did not probe all nodes. In that case, we * skip the clean up for now, since we could remove nodes that - * were still on the bus. The bus reset increased hi->reset_sem, - * so there's a bus scan pending which will do the clean up - * eventually. + * were still on the bus. Another bus scan is pending which will + * do the clean up eventually. * * Now let's tell the bus to rescan our devices. This may seem * like overhead, but the driver-model core will only scan a @@ -1607,41 +1602,37 @@ static int nodemgr_host_thread(void *__hi) { struct host_info *hi = (struct host_info *)__hi; struct hpsb_host *host = hi->host; - int reset_cycles = 0; - - /* No userlevel access needed */ - daemonize(hi->daemon_name); + unsigned int g, generation = get_hpsb_generation(host) - 1; + int i, reset_cycles = 0; /* Setup our device-model entries */ nodemgr_create_host_dev_files(host); - /* Sit and wait for a signal to probe the nodes on the bus. This - * happens when we get a bus reset. */ - while (1) { - unsigned int generation = 0; - int i; + for (;;) { + /* Sleep until next bus reset */ + set_current_state(TASK_INTERRUPTIBLE); + if (get_hpsb_generation(host) == generation) + schedule(); + __set_current_state(TASK_RUNNING); + + /* Thread may have been woken up to freeze or to exit */ + if (try_to_freeze()) + continue; + if (kthread_should_stop()) + goto exit; - if (down_interruptible(&hi->reset_sem) || - down_interruptible(&nodemgr_serialize)) { + if (down_interruptible(&nodemgr_serialize)) { if (try_to_freeze()) continue; - printk("NodeMgr: received unexpected signal?!\n" ); - break; - } - - if (hi->kill_me) { - up(&nodemgr_serialize); - break; + goto exit; } /* Pause for 1/4 second in 1/16 second intervals, * to make sure things settle down. */ + g = get_hpsb_generation(host); for (i = 0; i < 4 ; i++) { - set_current_state(TASK_INTERRUPTIBLE); - if (msleep_interruptible(63)) { - up(&nodemgr_serialize); - goto caught_signal; - } + if (msleep_interruptible(63) || kthread_should_stop()) + goto unlock_exit; /* Now get the generation in which the node ID's we collect * are valid. During the bus scan we will use this generation @@ -1652,14 +1643,8 @@ static int nodemgr_host_thread(void *__hi) /* If we get a reset before we are done waiting, then * start the the waiting over again */ - while (!down_trylock(&hi->reset_sem)) - i = 0; - - /* Check the kill_me again */ - if (hi->kill_me) { - up(&nodemgr_serialize); - goto caught_signal; - } + if (generation != g) + g = generation, i = 0; } if (!nodemgr_check_irm_capability(host, reset_cycles) || @@ -1685,11 +1670,11 @@ static int nodemgr_host_thread(void *__hi) up(&nodemgr_serialize); } - -caught_signal: +unlock_exit: + up(&nodemgr_serialize); +exit: HPSB_VERBOSE("NodeMgr: Exiting thread"); - - complete_and_exit(&hi->exited, 0); + return 0; } int nodemgr_for_each_host(void *__data, int (*cb)(struct hpsb_host *, void *)) @@ -1749,41 +1734,27 @@ static void nodemgr_add_host(struct hpsb_host *host) struct host_info *hi; hi = hpsb_create_hostinfo(&nodemgr_highlevel, host, sizeof(*hi)); - if (!hi) { - HPSB_ERR ("NodeMgr: out of memory in add host"); + HPSB_ERR("NodeMgr: out of memory in add host"); return; } - hi->host = host; - init_completion(&hi->exited); - sema_init(&hi->reset_sem, 0); - - sprintf(hi->daemon_name, "knodemgrd_%d", host->id); - - hi->pid = kernel_thread(nodemgr_host_thread, hi, CLONE_KERNEL); - - if (hi->pid < 0) { - HPSB_ERR ("NodeMgr: failed to start %s thread for %s", - hi->daemon_name, host->driver->name); + hi->thread = kthread_run(nodemgr_host_thread, hi, "knodemgrd_%d", + host->id); + if (IS_ERR(hi->thread)) { + HPSB_ERR("NodeMgr: cannot start thread for host %d", host->id); hpsb_destroy_hostinfo(&nodemgr_highlevel, host); - return; } - - return; } static void nodemgr_host_reset(struct hpsb_host *host) { struct host_info *hi = hpsb_get_hostinfo(&nodemgr_highlevel, host); - if (hi != NULL) { - HPSB_VERBOSE("NodeMgr: Processing host reset for %s", hi->daemon_name); - up(&hi->reset_sem); - } else - HPSB_ERR ("NodeMgr: could not process reset of unused host"); - - return; + if (hi) { + HPSB_VERBOSE("NodeMgr: Processing reset for host %d", host->id); + wake_up_process(hi->thread); + } } static void nodemgr_remove_host(struct hpsb_host *host) @@ -1791,18 +1762,9 @@ static void nodemgr_remove_host(struct hpsb_host *host) struct host_info *hi = hpsb_get_hostinfo(&nodemgr_highlevel, host); if (hi) { - if (hi->pid >= 0) { - hi->kill_me = 1; - mb(); - up(&hi->reset_sem); - wait_for_completion(&hi->exited); - nodemgr_remove_host_dev(&host->device); - } - } else - HPSB_ERR("NodeMgr: host %s does not exist, cannot remove", - host->driver->name); - - return; + kthread_stop(hi->thread); + nodemgr_remove_host_dev(&host->device); + } } static struct hpsb_highlevel nodemgr_highlevel = { -- 2.39.5